28145779 has 4 divisors (see below), whose sum is σ = 28800376. Its totient is φ = 27491184.

The previous prime is 28145723. The next prime is 28145791. The reversal of 28145779 is 97754182.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28145779 - 2⁷ = 28145651 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43), and also a Moran number because the ratio is a prime number: 654553 = 28145779 / (2 + 8 + 1 + 4 + 5 + 7 + 7 + 9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28145879) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 327234 + ... + 327319.

It is an arithmetic number, because the mean of its divisors is an integer number (7200094).

Almost surely, 2^28145779 is an apocalyptic number.

28145779 is a deficient number, since it is larger than the sum of its proper divisors (654597).

28145779 is an equidigital number, since it uses as much as digits as its factorization.

28145779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 654596.

The product of its digits is 141120, while the sum is 43.

The square root of 28145779 is about 5305.2595600969. The cubic root of 28145779 is about 304.1849744240.

The spelling of 28145779 in words is "twenty-eight million, one hundred forty-five thousand, seven hundred seventy-nine".